Re-architecture of the Godot Android plugin.

platform/android/java/app/AndroidManifest.xml

@@ -37,6 +37,11 @@
             android:name="xr_mode_metadata_name"
             android:value="xr_mode_metadata_value" />
 
+        <!-- Metadata populated at export time and used by Godot to figure out which plugins must be enabled. -->
+        <meta-data
+            android:name="custom_template_plugins"
+            android:value="custom_template_plugins_value"/>
+
         <activity
             android:name=".GodotApp"
             android:label="@string/godot_project_name_string"

platform/android/java/app/build.gradle

@@ -34,15 +34,30 @@ allprojects {
 
 dependencies {
     implementation libraries.supportCoreUtils
+    implementation libraries.v4Support
 
     if (rootProject.findProject(":lib")) {
         implementation project(":lib")
+    } else if (rootProject.findProject(":godot:lib")) {
+        implementation project(":godot:lib")
     } else {
         // Custom build mode. In this scenario this project is the only one around and the Godot
         // library is available through the pre-generated godot-lib.*.aar android archive files.
         debugImplementation fileTree(dir: 'libs/debug', include: ['*.jar', '*.aar'])
         releaseImplementation fileTree(dir: 'libs/release', include: ['*.jar', '*.aar'])
     }
+
+    // Godot prebuilt plugins
+    implementation fileTree(dir: 'libs/plugins', include: ["GodotPayment*.aar"])
+
+    // Godot user plugins dependencies
+    String pluginsDir = getGodotPluginsDirectory()
+    String[] pluginsBinaries = getGodotPluginsBinaries()
+    if (pluginsDir != null && !pluginsDir.isEmpty() &&
+        pluginsBinaries != null && pluginsBinaries.size() > 0) {
+        implementation fileTree(dir: pluginsDir, include: pluginsBinaries)
+    }
+
 //CHUNK_DEPENDENCIES_BEGIN
 //CHUNK_DEPENDENCIES_END
 }

platform/android/java/app/config.gradle

@@ -1,24 +1,63 @@
 ext.versions = [
-        androidGradlePlugin : '3.4.2',
-        compileSdk : 28,
-        minSdk : 18,
-        targetSdk : 28,
-        buildTools : '28.0.3',
-        supportCoreUtils : '28.0.0'
+    androidGradlePlugin: '3.4.2',
+    compileSdk         : 28,
+    minSdk             : 18,
+    targetSdk          : 28,
+    buildTools         : '28.0.3',
+    supportCoreUtils   : '28.0.0',
+    v4Support          : '28.0.0'
 
 ]
 
 ext.libraries = [
-        androidGradlePlugin : "com.android.tools.build:gradle:$versions.androidGradlePlugin",
-        supportCoreUtils : "com.android.support:support-core-utils:$versions.supportCoreUtils"
+    androidGradlePlugin: "com.android.tools.build:gradle:$versions.androidGradlePlugin",
+    supportCoreUtils   : "com.android.support:support-core-utils:$versions.supportCoreUtils",
+    v4Support          : "com.android.support:support-v4:$versions.v4Support"
 ]
 
 ext.getExportPackageName = { ->
-	// Retrieve the app id from the project property set by the Godot build command.
-	String appId = project.hasProperty("export_package_name") ? project.property("export_package_name") : ""
-	// Check if the app id is valid, otherwise use the default.
-	if (appId == null || appId.isEmpty()) {
-		appId = "com.godot.game"
-	}
-	return appId
+    // Retrieve the app id from the project property set by the Godot build command.
+    String appId = project.hasProperty("export_package_name") ? project.property("export_package_name") : ""
+    // Check if the app id is valid, otherwise use the default.
+    if (appId == null || appId.isEmpty()) {
+        appId = "com.godot.game"
+    }
+    return appId
+}
+
+/**
+ * Parse the project properties for the 'custom_template_plugins' property and return
+ * their binaries for inclusion in the build dependencies.
+ *
+ * The listed plugins must have their binaries in the project plugins directory.
+ */
+ext.getGodotPluginsBinaries = { ->
+    String[] binDeps = []
+
+    // Retrieve the list of enabled plugins.
+    if (project.hasProperty("custom_template_plugins")) {
+        String pluginsList = project.property("custom_template_plugins")
+        if (pluginsList != null && !pluginsList.trim().isEmpty()) {
+            for (String plugin : pluginsList.split(",")) {
+                binDeps += plugin.trim() + "*.aar"
+            }
+        }
+    }
+
+    return binDeps
+}
+
+/**
+ * Parse the project properties for the 'custom_template_plugins_dir' property and return
+ * its value.
+ *
+ * The returned value is the directory containing user plugins.
+ */
+ext.getGodotPluginsDirectory = { ->
+    // The plugins directory is provided by the 'custom_template_plugins_dir' property.
+    String pluginsDir = project.hasProperty("custom_template_plugins_dir")
+        ? project.property("custom_template_plugins_dir")
+        : ""
+
+    return pluginsDir
 }